1. Field of the Invention
The present invention relates to an apparatus for bending a thin flexible and narrow strip. More particularly, the present invention relates to an apparatus for bending a thin flexible and narrow strip of the type used for perforating or shearing paper sheets being printed wherein the strip is bent into a predetermined curved or circular shape.
2. The Prior Art
The present invention relates to bending of thin flexible and narrow strips of the type shown in Bashaw U.S. Pat. No. 3,035,342 and, in particular, to the bending of the strip such as shown in FIG. 9 of the Bashaw patent. As also indicated in the Bashaw patent, there is a demand in the printing industry for extremely thin and flexible strip having a series of upstanding teeth, or a continuous tooth or rib, extending along a longitudinal line on one face thereof, the opposite face being flat. Such a strip is employed for perforating or shearing the paper sheets being printed, and must be sufficiently flexible to permit its being bent around the cylinder of an off-set press, and secured thereto by means of a suitable adhesive. In the past, these strips are generally placed on the cylinder of the off-set press so as to provide essentially linear perforated or shear lines on the paper sheets.
Prior to the present invention, the industry has recognized the desire to bend a strip into predetermined curved or circular shapes so that circles or tear-drops, for example, can be sheared or perforated into the paper strips; however, since the rib or tooth portion must still be at right angles to the paper sheets, the bending of the flexible strip will have to be at right angles to the base portion of the strip. Efforts to bend the strip into predetermined geometric shapes have been, largely, unsuccessful.